1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Biology Sylvia S. Mader Michael Windelspecht Chapter 8 Digestive System and Nutrition Lecture Outline Part 4

2 Lipids Lipids include fats, oils, and cholesterol. _____________ (usually of animal origin) are usually solid at room temperature, while unsaturated fats are usually liquid at room temperature. Essential fatty acids are ones that must be ingested; they include linoleic acid and linolenic acid (these can only be found in polyunsaturated oils such as corn and safflower). 8.6 Nutrition and Weight Control

3 Lipids Olive and canola oil contain more monounsaturated fats. Omega-3 fatty acids, thought to ward off ____ _________, are found in some fish (salmon, sardines, and trout) as well as some plants (flaxseed oil). 8.6 Nutrition and Weight Control

4 Choosing the most healthy fat and oil Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display canola oil safflower oil olive oil beef fat butter coconut oil Percentages % saturated fat % monounsaturated fat % polyunsaturated fat % cholesterol Figure 8.14 Saturated and unsaturated fatty acids. 8.6 Nutrition and Weight Control

5 Can lipids be harmful? CVD is often a result of arteries blocked by plaque made of cholesterol and saturated fats. ___________________ (LDL) is the “bad” cholesterol because it carries cholesterol from the liver to the cells. LDL is increased by saturated fats and decreased by unsaturated fats. 8.6 Nutrition and Weight Control

6 _________________ (HDL) is the “good” cholesterol because it carries cholesterol to the liver where it is converted to bile salts. Trans-fatty acids are made by hydrogenation of unsaturated fatty acids for commercial products and may reduce the ability of cells to clear cholesterol from the bloodstream. 8.6 Nutrition and Weight Control Can lipids be harmful?

7 How can you reduce “bad” fats and cholesterol in your diet? 8.6 Nutrition and Weight Control

8 Minerals The body contains > 5g of each major mineral and < 5g of each trace mineral. Major minerals make up components of cells, body fluids, and tissues (i.e., calcium). Minor minerals are components of larger molecules (i.e., iron in hemoglobin). A varied and complete diet usually provides necessary minerals. 8.6 Nutrition and Weight Control

9 Calcium Calcium is needed to make bone, nerve impulse conduction, and muscle contraction. 1,000 mg/day are recommended to keep bones healthy early in life and 1,300 mg/day after menopausal age. Vitamin D is needed with calcium to prevent bone loss (_____________). 8.6 Nutrition and Weight Control

10 Sodium Sodium is needed for regulating water balance. 500 mg/day is the recommended amount (on average each American takes in ______ ______ mg/day). Sodium can increase hypertension in people who already have it. 8.6 Nutrition and Weight Control

11 A summary of minerals 8.6 Nutrition and Weight Control

12 Vitamins Organic compounds (not including proteins, fats, or carbohydrates) are used for metabolism but not produced in high enough quantities by the body. Vitamins are often enzyme helpers (coenzymes). There is a total of 13 vitamins in 2 groups: ________ and __________. 8.6 Nutrition and Weight Control

13 Fat-soluble vitamins 8.6 Nutrition and Weight Control

14 Water-soluble vitamins 8.6 Nutrition and Weight Control

15 Antioxidants Antioxidants are chemicals that decrease the rate of oxidation or transfer of electrons. Vitamin C, E, and A are considered antioxidants because they are thought to defend the body against free radicals that can transfer electrons and damage cells and DNA. The vitamins are common in fruits and vegetables. 8.6 Nutrition and Weight Control

16 A guide to daily food recommendations 8.6 Nutrition and Weight Control Figure 8.15 MyPlate. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. USDA, ChooseMyPlate.gov website Fruits Grains Protein Vegetables Dairy ChooseMyplate.gov

17 Eating disorders _____________ – psychological disorder due to fear of getting fat; usually results in self-induced starvation, high physical activity, and may include purging _____________ – disorder in which people eat large amounts of high-calorie food (binge-eating) followed by purging to avoid weight gain, often more than once a day 8.6 Nutrition and Weight Control

18 Eating disorders ___________________ – obese people are afflicted; overeating is not followed by purging, and this can lead to depression, anger, anxiety, and more binges ___________________ – characterized by people that think their bodies are underdeveloped and are often preoccupied with body-building activities and diet 8.6 Nutrition and Weight Control

19 Eating disorders are associated with body image Figure 8.16 The characteristics of different eating disorders. 8.6 Nutrition and Weight Control Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a. Anorexia nervosab. Bulimia nervosac. Muscle dysmorphia a: © Ted Foxx/Alamy RF; b: © Donna Day/Stone/Getty Images; c: © Corbis RF